1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
* ECB/CBC Padding Methods
* (C) 1999-2008,2013 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_MODE_PADDING_H__
#define BOTAN_MODE_PADDING_H__
#include <botan/secmem.h>
#include <string>
namespace Botan {
/**
* Block Cipher Mode Padding Method
* This class is pretty limited, it cannot deal well with
* randomized padding methods, or any padding method that
* wants to add more than one block. For instance, it should
* be possible to define cipher text stealing mode as simply
* a padding mode for CBC, which happens to consume the last
* two block (and requires use of the block cipher).
*/
class BOTAN_DLL BlockCipherModePaddingMethod
{
public:
virtual void add_padding(secure_vector<byte>& buffer,
size_t final_block_bytes,
size_t block_size) const = 0;
/**
* @param block the last block
* @param size the of the block
*/
virtual size_t unpad(const byte block[],
size_t size) const = 0;
/**
* @param block_size of the cipher
* @return valid block size for this padding mode
*/
virtual bool valid_blocksize(size_t block_size) const = 0;
/**
* @return name of the mode
*/
virtual std::string name() const = 0;
/**
* virtual destructor
*/
virtual ~BlockCipherModePaddingMethod() {}
};
/**
* PKCS#7 Padding
*/
class BOTAN_DLL PKCS7_Padding : public BlockCipherModePaddingMethod
{
public:
void add_padding(secure_vector<byte>& buffer,
size_t final_block_bytes,
size_t block_size) const override;
size_t unpad(const byte[], size_t) const override;
bool valid_blocksize(size_t bs) const override { return (bs > 0 && bs < 256); }
std::string name() const override { return "PKCS7"; }
};
/**
* ANSI X9.23 Padding
*/
class BOTAN_DLL ANSI_X923_Padding : public BlockCipherModePaddingMethod
{
public:
void add_padding(secure_vector<byte>& buffer,
size_t final_block_bytes,
size_t block_size) const override;
size_t unpad(const byte[], size_t) const override;
bool valid_blocksize(size_t bs) const override { return (bs > 0 && bs < 256); }
std::string name() const override { return "X9.23"; }
};
/**
* One And Zeros Padding
*/
class BOTAN_DLL OneAndZeros_Padding : public BlockCipherModePaddingMethod
{
public:
void add_padding(secure_vector<byte>& buffer,
size_t final_block_bytes,
size_t block_size) const override;
size_t unpad(const byte[], size_t) const override;
bool valid_blocksize(size_t bs) const override { return (bs > 0); }
std::string name() const override { return "OneAndZeros"; }
};
/**
* Null Padding
*/
class BOTAN_DLL Null_Padding : public BlockCipherModePaddingMethod
{
public:
void add_padding(secure_vector<byte>&, size_t, size_t) const override {}
size_t unpad(const byte[], size_t size) const override { return size; }
bool valid_blocksize(size_t) const override { return true; }
std::string name() const override { return "NoPadding"; }
};
BlockCipherModePaddingMethod* get_bc_pad(const std::string& algo_spec);
}
#endif
|
